perhaps the easiest solution would be to modify the vari-speed,
assuming it has one IF one could figure the proper resistance required
and replace the pot of the 45 position, what else would you need?
David Lennick wrote:
> Anyone have any thoughts on this? Enrico Borsetti is an ARSC member but
> not subscribed to the list.
> enrico borsetti wrote:
>> I had an idea recently regarding a modification on a turntable I have.
>> I am using for the 26th year my loyal Revox B790 linear tracking
>> turntable but it has only 33 and 45 speeds. I have many 78 rpm records
>> and I want to buy another B790 since being linear tracking it gives
>> no aural distortion when the arm get close to the label as you know.
>> The speed control unit, which is made by easy to find IC's, should be
>> modified in manner to let the table spin at 78. I have the schematic
>> of the motherboard and arm control unit of the B790. Today the whole
>> work done by these old IC's can be made with a single PIC
>> microcontroller (http://en.wikipedia.org/wiki/PIC_microcontroller).
>> Do you know of any Electronic engineer (and record collector at the
>> same time) interested to take part in this 'upgrade' project?
>> I think this 'upgrade' project could be of interest to many collectors
>> and our 78-L friends since this 'table pops-up often on ebay and at
>> reasonable prices, I saw it around $200/$300 in working condition. If
>> the upgrade will be produced in a certain quantity the motherboard
>> cost will be around $60 if not even less. So within $350 you can play
>> your 78's but with the quality of a linear tracking table!
>> Let me know what you think about it.
>> All the best Enrico
> Replies will be forwarded. Thanks!